Papermaker&#39;s wet felt



May 16, 1961 H. M. HELLAND PAPERMAKERSWET FELT Filed June 23. 1958 o/REcr/ON of:

BELT TRA VEL.

INVENTOR: Hon/,4R0 M. HL-L AA/D BY.' @dag M, Mz* @afg A7 7ORNEYS.

,une y United States Patent() "i PAPERMAKERS WET FELT Howard M. Helland, Newfane, N.Y., assignor to Lockport -Felt Company, Inc., Newfane, N.Y.

Filed June z3, 195s, ser. No. 743,624 1 claims. (c1. zs 7s) This invention relates to improvements in construction of papermakers felts such as are used in the manufacture of paper, paper board, pulp, asbestos shingles, Transite pipes, and like products.A IFor example, the invention `relates generally to improvements in the art referred to in my previously tiled application Serial No. 719,586, filed March 6, 1958.

It is a primary object of the present invention to provide for the papermakers felt art speciiically, an improved `felt constructed of fibres, such as any .of theV conventionally used grades of wool, cotton, or other,

natural or synthetic vfibres or combinations thereof; fabricated by means of a novel technique in this art so as to provide an improved papermakers felt of many advantages.

A more specific object of the invention is to provide a felt as aforesaid which presents a working surface of improved smoothness and pulp supporting and cushioning characteristics.

Another object is to provide a felt aforesaid which is of improved etciency as a drainage lter in its intended use. Y l

Another object is to provide an improved felt as aforesaid which obtains maximum strength effects in the direction of the load. p

. Still another object of the invention isv to provide a felt as aforesaid which also is of improved dimensional stability characteristics.

Another object is to provide an improved felt .as

aforesaid which is of such construction that whenever theV load on the felt is relaxed the pores of the fabric tend to open,` thereby facilitating cleaning of the felt.

v Other objects and advantages of the invention will appear from the specification hereinafter, and the accompanying drawings, wherein:

Fig. 1 is a diagrammatic perspective view of one form of plied yarn such as may be employed in construction of a felt of the present invention;

Fig. 2 is a laterally distorted diagrammatic plan view (at reduced scale) o f a swatch of fabric, illustrating the weave pattern employed in manufacturev of the felt;

Fig. 3 is adiagrammatic plan view corresponding to Fig. 2 but of a swatch of the fabrication as it actually appears subsequent to initial weaving thereof; and ,5

Fig. 4 is a diagrammatic fragmentary sectional view taken along line IV-IV of Fig. 3, but subsequentto final processing of the fabrication.

In the papermakers wet'felt art a prime d-esideratum is to provide ajfabric structure which is longitudinally strong while at the same time comprising an ecient water-drainage or filter membrane in the form of a resilient mass. For such purposes the woolV and/or other fibres used must be so integrated as to present to the pulp being treated a uniformly smooth and level yet resilient surface. The present invention provides the desired results through use of a novel fabrication of yarns wherein the individual -bres subsequent to the yarn interlocking operation are as free as possible'to move rel- Patented May 16,1961

ative to one another during the fabric fulling or milling operations.

Thus, the invention contemplates that the yarns be relatively interlocked in a novel manner in this art, so that when the yarns are worked into the fabrication the individual libres `thereof are under minimum constraint. This effect may be obtained by employing an interlock pattern involving only generally parallel warp yarns which are intertwined in novel manner. Preferably, at least a large percentage of these yarns will beV of such form that the fibres thereof are substantially untwisted, as compared to conventionally twisted 4fibre yarns as are usually employed in this art. The yarns employed may be produced by either the so-called woolen system or any of the so-called worsted systems, and may be either singles or plied yarns. More specifically, the invention contemplates a felt fabrication comprising solely generally parallel .yarns which are preferably of substantially untwisted form, so integrated during the fabrication process as to produce a novel felt construction wherein the relatively soft yarns are enin Fig. 1 may be plied as by means of a neutralizing Z twist. Hence, the resultant plied yarn designated generally at 15 comprises intertwined singles yarns, the individual libres 10 of which are as near as possible untwisted. By way of a specific example, the card roping may be initially drafted and S twisted at the rate of say 4.0 t.p.i. (twists per inch), according to the libre lengths and other variables. The two singles yarns so produced may then be relatively entwined by means of a neutralizing Z twist in such manner as to provide a plied yarn of say 4.5 t.p.i. Experience indicates that approximately such a ratio of singles and plied yarn twists will result in production of a plied yarn as indicated at 15 in the drawing wherein the individual fibres are only very slightly twisted (in one direction or thev other) or are substantially untwisted about their own axes, while gently winding spirally about the neutral axis of 'the yarn. In the alternative, the card roping may be formed into singles yarn stock by means of a Z twist operation, and the singles yarns may thereupon be S twisted into plied yarn form, to provide the plied yarn stock 15 as explained hereinabove. In either case the yarn stock may be described as comprising two groups o f untwisted fibres gently rolling around one another. Due tothe fact that the singles yarns are relatively entwined the overall structure of the plied yarns 15 has adequate strength to withstand the subsequent weaving operation, in spite of the fact that the individual fibres are substantially untwisted.

As the second phase of the manufacture of the fabric,

ypluralities of the yarns 15 are intertwined as shown in Fig. 2 wherein the construction is illustrated as when being laterally stretched out of natural condition to facilitate understanding of the nature of the yarn interweaving system. Thus, when the structure is relaxed to its normal condition as shown in Fig. 3, the yarns 15 are interlinked and nested together in a manner quite unique in the wet felt art. This fabric is then submitted to any suitable shrinking and fulling or milling operations; and thus the fabric is shrunk and fulled as into the form illustrated by Fig. 4. As shown in Fig. 3, the yarns 15 are substantially straightened out plan view to their conditions of maximum efficiency with respect to resistance to tension loads on the felt. It will of course be understood that the fabric of the invention may be constructed by any suitable type machine. l

Whereas, they yarns 1-5, due to their relatively entwined positions in the interlock pattern acquire optimum felt tension resistance characteristics, the locally soft nature of the yarn stock permit them to easily deform and bulk out and respond in improved manner to the fulling treatment because the individual fibres thereof are of improved mobility. Hence, in the resulting felt fabrication the fibres' provide a mat of superior surface smoothness and cushioning characteristics. the double thickness and laterally unrestrained nature of the interlock pattern permits the fabric to breathe and to operate with maximum efliciency in accord with the phenomenon of capillarity and in response to the pumping action within the felt when passing through compression rolls; thereby improving its water removing abilities. For the same reason the fabric is of improved inherent self-cleaning characteristics and is more responsive to conventional cleaning devices than are felts of other construction. Thus, each libre of the fabrication is disposed to act more efiiciently in its assigned task.

By virtue of the present invention a wet felt of more open or coarser structure may be made to meet specifications heretofore met only by felts of finer construction. Yet, by reason of the more efficient bulking of the fibres in the felt of the invention, it is also of superior surface or finish characteristics. Hence, these new felts will be of superior drainage characteristics because the total felt weight may be lowered.

It is a particular feature of the invention that in the finished felt belt the individual yarns and fibres are disposed at only slightly oblique angles to the direction of belt travel (Fig. 3); thereby providing a felt of increased total load pulling power for the same felt weight, and avoiding head-on impacts of yarn rises or oats against stationary equipment such as suction boxes, cleaning shoes, etc.

It will of course be appreciated that the invention is not limited to the precise constructions illustrated herein nor to the specific wet felt usage described hereinabove, and that the construction may be modified without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. A new papermakers felt for supporting and draining paper making material, said felt comprising a beltlike fabric structure having only substantially untwisted yarns running generally lengthwise of the belt each of said yarns following a slightly zig-zag course and hooking first around the next adjacent yarn at one side thereof and then around the next adjacent yarn at the opposite side thereof and so on throughout the length of the belt, the individual fibres of said yarns being spirally wound but substantially untwisted about their own axes, said yarns each comprising card roping twisted only slightly into twisted yarn form, said fabric being fulled.

2. A new papermakers felt for supporting and draining paper making material, said felt comprising a beltlike fabric formed solely of relatively soft twisted yarns running lengthwise thereof each of said yarns following a slightly zig-zag course and hooking first around the next adjacent yarn at the opposite side thereof and so on throughout the length of the belt, the individual At the same time.

4 a. fibres of said yarns being substantially untwisted about their own axes, said fabric being fulled.

3. A new papermakers felt for supporting and draining paper making material, said felt comprising a beltlike structure having only substantially untwisted plied yarns running generally lengthwise thereof each of said yarns following a slightly zig-zag course and hooking first around the next adjacent yarn at the opposite side thereof and so on throughout the length of the belt, the individual fibres of said yarns being spirally wound but substantially untwisted about their own axes, said plied yarns each comprising a pair of singles yarns each comprising card roping twisted into conventional S twisted yarn form and Z twisted together in opposite direction into plied yarn form, said interlocked yarns being fulled.

4. A new papermakers felt fabric for supporting and draining paper making material, said felt comprising a belt-like structure having relatively soft twisted plied yarns running lengthwise thereof each of said yarns following a slightly zig-zag course and hooking first around the next adjacent yarn at the opposite side thereof and so on throughout the length of the belt, the individual libres of said yarns being substantially untwisted about their own axes, said yarns each comprising a pair of singles yarns twisted together into plied yarn form, said fabric being fulled.

5. A new papermakers felt fabric for supporting and draining paper making material, said felt comprising a belt-like structure having relatively soft-twisted plied yarns running lengthwise thereof each of said yarns following a slightly zig-zag course and hooking first around the next adjacent yarn at the opposite side thereof and so on throughout the length of the belt, said yarns having their individual fibres substantially untwisted about their own axes 'and each comprising a pair of singles yarns S twisted together into plied yarn form, each of said single yarns comprising card roping Z twisted in opposite direction into singles yarn form, said fabric being fulled.

6. A papermakers felt for supporting and draining paper making material, said felt comprising a fabric structure having plied yarns running lengthwise thereof each of said yarns following a slightly zig-zag course and hooking first around the next adjacent yarn at the opposite side thereof and so on throughout the length of the felt, said yarns each comprising a plurality of singles yarns twisted together into plied yarn form, each of said singles yarns comprising card roping twisted into yarn form, said fabric being fulled.

7. A new papermakers felt for supporting and draining paper making material, comprising a fabric structure having yarns running only lengthwise of the fabric each of said yarns following a slightly zig-zag course and hooking rst around the next adjacent yarn at the opposite side thereof and so on throughout the length of the felt, each yarn being thereby interlocked alternately with the yarns oppositely adjacent thereto, said fabric being fulled.

References Cited in the file of this patent UNITED STATES PATENTS 255,407 Beals Mar. 28, 1882 1,497,068 Collingbourne June 10, 1924 2,423,828 Chagnon Iuly 15, 1947 OTHER REFERENCES Effect of Ply Twist on Single Twist from Textile World, February 21, 1931. Page 38. Copy in 57-139. 

